ECS markers in oligodendrocyte development

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This analysis was performed by MCB Lab.

Introduction

Early life stress (ELS) profoundly influences brain development by altering oligodendrogenesis and myelination, processes regulated by both glucocorticoids and the endocannabinoid system (ECS). In the referenced study, maternal separation combined with corticosterone exposure accelerated oligodendrocyte lineage progression and myelin marker expression in neonatal mice. These effects were modulated by CB1 receptor activity and 2-AG signaling, highlighting ECS–HPA axis interplay in myelin plasticity. To support these findings, we used the single-cell RNA-seq dataset from Dennis et al. (2024) [GSE237672] to better understand the expression dynamics of ECS and glucocorticoid signaling components across oligodendrocyte lineage cells during early postnatal brain development.

Dataset used can be found in Dennis et al publication.

Questions

1. Which cell types during early postnatal express glucorticoid receptors and canabinoid receptors as CB1 / CB2?
2. Does it have a specific OPCs / Oligodendrocytes groups expressing those markers?

Results

Cell types were annotated following mostly protocol established by Dennis et al publication.

Which cell types during early postnatal express glucorticoid receptors and canabinoid receptors as CB1 / CB2?

UMAP to overview annotated cell groups, time, area and cell phase.

Markers used by author to classify cells

Does it have a specific OPCs / Oligodendrocytes groups expressing those markers?

Differential Gene Expression

Table with all markers found within each Time + Area for subpopulations of OPCs + OLs.

Column	Description
Gene	The gene symbol or ID of the marker gene identified as differentially expressed. Each entry corresponds to one gene tested across clusters or groups.
Cluster	The cell cluster (or subpopulation) in which the gene is more highly expressed compared to others. For example, a specific OPC or OL subtype.
Area	The anatomical region (e.g., cortex, corpus callosum, spinal cord) where this cluster’s cells were sampled. Helps distinguish spatial differences in gene expression.
Age	The time point or developmental stage (e.g., P7, Adult) at which cells were collected. Allows temporal comparisons of expression changes.
avg_log2FC	The average log₂ fold-change in expression between cells in the cluster of interest and all other cells. Positive values indicate upregulation in this cluster; negative values indicate downregulation.
pct.1	The percentage of cells in the target cluster where this gene is detected (nonzero expression). Higher values = more consistently expressed within the cluster.
pct.2	The percentage of cells in all other clusters (combined) expressing the same gene. Used to assess specificity of expression.
p_val_adj	The adjusted p-value (after multiple testing correction, e.g., Bonferroni or FDR) indicating the statistical significance of the differential expression. Smaller values = stronger evidence that the gene is a true marker.